Design and Testing of a Multi-Hole Probe Geometry Insensitive to Manufacturing Variance

Multi-hole probes are aerodynamic instruments that measure pressure at various points on their geometry. This array of pressures is used to estimate airspeed and flow angles through an established mathematical relationship. For existing multi-hole probes, this relationship is highly sensitive to the particular geometry of the probe. Due to manufacturing variances, each probe requires a unique calibration for its specific geometry, which is expensive and time consuming. Typical multi-hole probe configurations include hemispherical, conical, and pyramidal tip geometries. This project considers six probes spanning these common configurations and seeks to identify which geometry is least sensitive to manufacturing variance utilizing Reynolds-Averaged Navier-Stokes computational fluid dynamic simulations. These probes are tested for a range of simulated manufacturing variances, including non-uniform scaling, pressure port displacement, bumps and dips on the surface, and skewed geometries. The consistency of the pressure measurements from these probe geometries is compared for equivalent manufacturing variances. In future work, the least sensitive probe geometry will be manufactured through a stereolithographic additive manufacturing technique and evaluated experimentally.